REAL-TIME CLOCK
RP/ RF/ RS5C62
APPLICATION MANUAL
ELECTRONIC DEVICES DIVISION
NO.EA-012-9803
NOTICE
1. The products and the product specifications described in this application manual are subject to change or dis-
continuation of production without notice for reasons such as improvement. Therefore, before deciding to use
the products, please refer to Ricoh sales representatives for the latest information thereon.
2. This application manual may not be copied or otherwise reproduced in whole or in part without prior written con-
sent of Ricoh.
3. Please be sure to take any necessary formalities under relevant laws or regulations before exporting or other-
wise taking out of your country the products or the technical information described herein.
4. The technical information described in this application manual shows typical characteristics of and example
application circuits for the products. The release of such information is not to be construed as a warranty of or a
grant of license under Ricoh's or any third party's intellectual property rights or any other rights.
5. The products listed in this document are intended and designed for use as general electronic components in
standard applications (office equipment, computer equipment, measuring instruments, consumer electronic
products, amusement equipment etc.). Those customers intending to use a product in an application requiring
extreme quality and reliability, for example, in a highly specific application where the failure or misoperation of
the product could result in human injury or death (aircraft, spacevehicle, nuclear reactor control system, traffic
control system, automotive and transportation equipment, combustion equipment, safety devices, life support
system etc.) should first contact us.
6. We are making our continuous effort to improve the quality and reliability of our products, but semiconductor
products are likely to fail with certain probability. In order prevent any injury to persons or damages to property
resulting from such failure, customers should be careful enough to incorporate safety measures in their design,
such as redundancy feature, fire-containment feature and fail-safe feature. We do not assume any liability or
responsibility for any loss or damage arising from misuse or inappropriate use of the products.
7. Anti-radiation design is not implemented in the products described in this application manual.
8. Please contact Ricoh sales representatives should you have any questions or comments concerning the prod-
ucts or the technical information.
June 1995
RP/RF/RS5C62
APPLICATION MANUAL
CONTENTS
......................................................................................................
1
FEATURES
....................................................................................................
1
BLOCK DIAGRAM
.........................................................................................
1
PIN CONFIGURATION
...................................................................................
2
PIN DESCRIPTION
........................................................................................
2
ABSOLUTE MAXIMUM RATINGS
...................................................................
3
RECOMMENDED OPERATING CONDITION
....................................................
3
DC ELECTRICAL CHARACTERISTICS
...........................................................
4
AC ELECTRICAL CHARACTERISTICS
...........................................................
5
TIMING CHART
.............................................................................................
5
FUNCTIONAL DESCRIPTION
.........................................................................
6
1. Addressing
.................................................................................................
6
2. Functions of Registers
...................................................................................
7
3. Functions of Counters
..................................................................................
15
USAGE
........................................................................................................
17
1. Reading and Writing Operations
......................................................................
17
2. Handling of CE Pin
......................................................................................
18
3. Configuration of Oscillatory Circuit
....................................................................
19
4. Adjustment of Oscillation Frequencies
...............................................................
20
5. Interrupts
.................................................................................................
22
6. Timer
......................................................................................................
23
7. Detection of Stop of Oscillation
........................................................................
24
8. Typical Power Supply Circuit
...........................................................................
25
9. Typical Connection between RP/RF/RS5C62 and CPU
...........................................
26
10. Typical Characteristics
..................................................................................
27
11. Typical Software-controlled Processes
...............................................................
29
OUTLINE
QUESTIONS AND ANSWERS ON USE
.........................................................
34
PACKAGE DIMENSIONS
..............................................................................
42
TAPING SPECIFICATIONS
...........................................................................
43
REAL-TIME CLOCK
RP/RF/RS5C62
OUTLINE
The RP/RF/RS5C62 are CMOS LSIs which serve microcomputers as real-time clocks providing time, calendar,
and alarm functions in direct coupling with the data buses of CPUs such as 8086 and 68000. A built-in timer counter
acts as a watchdog timer or interrupt timer. They are available in three different types of packages: the DIP type,
the SOP type, and the SSOP type.
FEATURES
• Directly connected to CPU, enabling fast access.
• 4bit bidirectional data bus, and 4bit address bus.
• The oscillator is driven by a constant voltage, so the oscillation frequency is stable even when the power supply
voltage fluctuates.
• Built-in timer counter using internal clock.
• Generates cyclic CPU interrupts, and generates alarm-match interrupts.
• Interrupt flag and interrupt inhibit.
• Clock (hour, minute, second), calendar (leap year, year, month, day, day-of-the-week), alarm (hour, minute).
• 12-or 24-hour mode is selectable.
• Recognizes leap years automatically.
• All clock and alarm data expressed in BCD codes.
• ±30 seconds adjustment function.
• Determines whether clock data is valid or invalid.
• Consumes very low power due to CMOS technology, so it can be backed up by batteries.
• Power supply voltage between 3.0 to 5.0V.
• Time keeping supply voltage between 2.0 to 6.0V.
• Package : 18pin DIP for RP5C62, 18pin SOP for RF5C62, 20pin SSOP for RS5C62.
BLOCK DIAGRAM
OSCIN
OSCOUT
OSC
DIV
WATCH & CALENDAR
OSC DETECT
COMPARATOR
INTERRURT
CONTROL
INTR
CE
CS
ALARM REGISTER
TMOUT
RD
WR
CONTROL REGISTER
TIMER
DATA BUS
CONTROL
ADDRESS BUS
CONTROL
ADDRESS
DECODER
VDD
VSS
D0D1D2 D3
A0 A1 A2 A3
1
京公网安备 11010802033920号
EEWORLD
